Chapter 10 Flashcards
what is photosynthesis?
photosynthesis is the process that converts solar energy into chemical energy
what are autotrophs?
autotrophs sustain themselves without eating anything derived from other organisms, able to produce organic molecules from CO2
Who are photoautotraphs?
Almost all plants, because they use the energy of the sun to make organic molecules
Where does photosynthesis occur?
in plants, algae, certain unicellular eukaryotes, and prokaryotes
What are heterotrophs?
heterotrophs obtain their organic material from other organisms, they consume, humans depend on photoautotrophs for food and oxygen
What are the major locations of photosynthesis?
leaves, chloroplasts are found mainly in cells of mesophyll (interior tissue of the leaf)
How many chloroplasts does each mesophyll cell have?
30-40 chloroplasts
What is stomata?
Microscopic pores on the leaf where CO2 enters and O2 exits
What is chlorophyll?
The pigment that gives leaves their green color and resides in the thylakoid membranes
What does photosynthesis produce?
CO2 is consumed and converted to sugar and oxygen
How do chloroplasts split water?
chloroplasts split water into hydrogen and oxygen: incorporating the electrons of hydrogen into sugar molecules and releasing oxygen as a by-product
What type of process is photosynthesis?
Photosynthesis is a redox process
What is oxidized and what is reduced in photosynthesis?
Water is oxidized and CO2 is reduced
Use thermodynamic terms to describe photosynthesis
Photosynthesis absorbs energy making it nonspontaneous, meaning it is endergonic, has a positive delta G, and is anabolic
What does photosynthesis consist of?
consists of the light reactions (photo part) and Calvin cycle (synthesis part)
what does the light reactions do in the thylakoids?
splits h20 to produce O2, reduce electron acceptor NADP+ to NADPH, and generates ATP from ADP by photophosphorylation
what is the source of oxygen in photosynthesis?
WATER
What does the Calvin Cycle (in the stroma) form?
it forms sugar from CO2, using ATP and NADPH
What does the Calvin cycle begin with?
Carbon fixation: incorporating CO2 into organic molecules
what are light dependent reactions?
they use light energy to make two molecules needed for the next stage of photosynthesis : energy storage molecule (ATP) and reduced electron carrier (NADPH)
products of light dependent reactions used in Calvin cycle are** slide 19
ATP and NADPH, and O2
what is wavelength?
wavelength is the distance between crests of waves
what does wavelength determine?
wavelength determines the type of electromagnetic energy
what does visible light consist of?
visible light consists of wavelengths that produce colors we can see
what are pigments? what is the relationship to wavelengths?
pigments are substances that absorb visible light, and different pigments absorb different wavelengths
what do wavelengths do if they are not absorbed or reflected?
they are transmitted
why do leaves appear green?
because chlorophyll reflects and transmits green light
what does light go through in a chloroplast?
light goes through the granum to produce transmitted light
what is an absorption spectrum?
an absorption spectrum is a graph plotting a pigment’s light absorption versus wavelength
what does absorption spectrum of chlorphyll a suggest?
suggests that violet-blue and red light work best for photosynthesis